I recently starts building freight car kits that I had sitting around for 15 years plus.  The layout has finally gotten to the point that I need to increase the freight car fleet. 

Yesterday I was reading Tony Thompson's blog and found his technique for weathering flat car decks, so I figured I'd give the method a try and add some variety to my flat car decks.  The site is at:

http://modelingthesp.blogspot.com/2011/05/weathering-flat-car-decks.html

I just received my ScaleTrains TTPX bulkhead flats.  While researching the exact cars I plan to model, I realized that many of the prototype cars have had their car numbers repainted into a standard (non-italic) font, while the alpha reporting marks themselves remain unchanged from their italicized factory font.

Here's an example of car with its factory number intact:

This is a multipart call for help. So I'd like to patch this loco out for my home road and fade the paint.

So do I do the paint fade first and then the patch out or the reverse of that procedure?

How do I get a good fade on black, we've all seen the ex PC locos that Conrail had they were almost gray?

And lastly I haven't decided on wether to do a complete patch out or fade the lettering to an almost unreadable state and put my reporting marks and number over those, what is the best way to fade out lettering/logos should I decide to do that?